At a Sunday night rally in Yao — Nippon Ishin’s strongest support base and the home of Osaka Gov. Ichiro Matsui — the party’s secretary-general, Hashimoto appealed to residents to approve the deployment of the tilt-rotor aircraft to Yao for training exercises with the U.S.

“If a huge earthquake occurs in the Nankai trough, we’ll have to rely on the U.S. military. It would be dangerous for (the Ospreys) to land at Yao airport for the first time after a quake occurred,” Hashimoto said of the forecast mega-temblor that could possibly occur anywhere, at any time, along the 4,000-km Pacific trench that runs from the Izu Peninsula to Shikoku.

“I’ve seen the airfield at Futenma. There’s no big difference between Futenma and Yao in terms of risk, and nobody has heard of an Osprey accident in Japan,” Hashimoto added.

The U.S. and Japan plan joint military training in Tokyo and other parts of Honshu this autumn for disaster response. The exercise assumes an earthquake has destroyed Tokyo or other cities along the Pacific coast, and will involve the Ospreys.

But Hashimoto and Matsui, who told reporters Sunday night he hoped other Kansai leaders would support bringing the Ospreys to Yao, face a tough road ahead.

Last week, the Yao Municipal Assembly passed a resolution opposing the Osprey deployment, citing safety concerns and the densely populated residential areas that immediately surround the airport. Only the four Nippon Ishin assembly members voted against the resolution.

Liberal Democratic Party Secretary-General Shigeru Ishiba, a former defense minister, said in late June that basing the Ospreys at Yao would be difficult because of the surrounding community. Nippon Ishin co-leader Shintaro Ishihara, whose public fighting with Hashimoto and Matsui has escalated recently, is also critical of the plan.

“It’s impossible. The Defense Ministry is laughing. Those Osaka leaders have no experience or perception of national politics,” Ishihara told reporters in Tokyo last month.

As mayor of the city of Osaka, Hashimoto has no direct authority over Yao